1. Field of the Invention
The present invention provides an aqueous fabric softener for the treatment of textiles based on water-insoluble nonionic surfactants whose emulsions or dispersions have been stabilized by the addition of protective colloids containing cationic groups.
2. Background of the Invention
The conventional laundry fabric softener, distearyl-dimethylammonium chloride (DSDMAC), has become subject to environmental discussion over the last few years owing to its aquatic toxicity. In the meantime, it has been replaced on the market by ester- or amide-containing quaternary ammonium bases or imidazolinium salts whose environmental characteristics are given a better rating.
In textile finishing, large amounts of noncationic auxiliaries, such as sulphonated fats, ethoxylates, silicones and waxes, are also successfully used for softening. Unlike household laundry fabric softening, softener emulsions are here applied in a relatively high concentration (10-50 g/l) by various methods, such as spraying, distribution or abstraction methods, depending on which softening effect is desired.
In contrast, a requirement of a good household laundry fabric softener is that it shows quantitative exhaustion onto the textiles to be treated from a highly dilute rinsing liquor emulsion (0.2 to 0.7 g/l). The well known effectiveness of the conventional cationic fabric softeners is based in particular on the distinct chemisorption of the emulsified cationic particles which are absorbed on the fiber by virtue of the ionic interaction with the anionic fiber surface. It is known from the literature that good softening effects can be achieved by mixing nonionic and cationic softeners. Thus, for example, fabric softener emulsions based on a mixture of lanolin or propoxylated lanolin and a conventional quaternary ammonium base which show good softening effects in laundry treatment (EP 0,086,104) have been proposed. A further advantage of these mixed emulsions is that they can be handled as highly concentrated emulsions without thickening, which often creates problems in the case of purely cationic active compound emulsions. The same effect is also achieved by other nonionic additives, such as, for example, alkylene oxide adducts of fatty alcohols, fatty acid amides and fatty acid esters and natural fats (EP 0,056,695; EP 0,159,919). Commercially available fabric softeners nowadays contain about 15% of co-softener, such as, for example, glycerol monostearate or fatty alcohol ethoxylates (Tenside Surf. Det. 27, 34-40 (1990)).